Results 31 to 40 of about 6,380 (236)
Unabsorbed Seyfert 2 galaxies [PDF]
Astronomy & Astrophysics, 2002 We present a sample of 17 type 2 Seyfert galaxies which have an X-ray column density lower than 10^{22} cm^{-2}. The Compton thin nature of these sources is strongly suggested by isotropic indicators. We estimate the fraction of these sources to be in the range of 10% - 30% of the population of type 2 Seyfert galaxies.
Panessa F., Bassani L.
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What We Talk about When We Talk about Blazars?
Frontiers in Astronomy and Space Sciences, 2017 After the discovery of powerful relativistic jets from Narrow-Line Seyfert 1 Galaxies, and the understanding of their similarity with those of blazars, a problem of terminology was born.
Luigi Foschini
doaj +1 more source
Large-Scale Environment Properties of Narrow-Line Seyfert 1 Galaxies at z < 0.4
Frontiers in Astronomy and Space Sciences, 2017 The large-scale environment is believed to affect the evolution and intrinsic properties of galaxies. It offers a new perspective on narrow-line Seyfert 1 galaxies (NLS1) which have not been extensively studied in this context before.
Emilia Järvelä +5 more
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Forty Years of X-Raying Narrow-Line Seyfert 1 Galaxies
Acta Polytechnica CTU Proceedings, 2014 Forty years after the discovery of Narrow-Line Seyfert 1 Galaxies (NLS1s), and 20 years since the discovery of the remarkable ultrasoft soft X-ray emissions of NLS1s, strategic publications improved the understanding of the Seyfert phenomenon more ...
Thomas Boller
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A New Sample of Gamma-Ray Emitting Jetted Active Galactic Nuclei—Preliminary Results
Universe, 2021 We are compiling a new list of gamma-ray jetted active galactic nuclei (AGN), starting from the fourth catalog of point sources of the Fermi Large Area Telescope (LAT).
Luigi Foschini +10 more
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Growth of Accreting Supermassive Black Hole Seeds and Neutrino Radiation
Journal of Astrophysics, Volume 2015, Issue 1, 2015., 2015 In the framework of microscopic theory of black hole (MTBH), which explores the most important processes of rearrangement of vacuum state and spontaneous breaking of gravitation gauge symmetry at huge energies, we have undertaken a large series of numerical simulations with the goal to trace an evolution of the mass assembly history of 377 plausible ...
Gagik Ter-Kazarian, Gary Wegner
wiley +1 more source
Retrograde versus Prograde Models of Accreting Black Holes
Advances in Astronomy, Volume 2013, Issue 1, 2013., 2013 There is a general consensus that magnetic fields, accretion disks, and rotating black holes are instrumental in the generation of the most powerful sources of energy in the known universe. Nonetheless, because magnetized accretion onto rotating black holes involves both the complications of nonlinear magnetohydrodynamics that currently cannot fully be
David Garofalo, Alberto J. Castro-Tirado
wiley +1 more source
Continuous Filament Network of the Local Universe
The Astrophysical Journal, 2023 Simulated galaxy distributions are suitable for developing filament detection algorithms. However, samples of observed galaxies, being of limited size, cause difficulties that lead to a discontinuous distribution of filaments.
Anatoliy Tugay, Mariusz Tarnopolski
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M94 as a Unique Testbed for Black Hole Mass Estimates and AGN Activity at Low Luminosities
Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 We discuss the peculiar nature of the nucleus of M94 (NGC 4736) in the context of new measurements of the broad Hα emission from HST‐STIS observations. We show that this component is unambiguously associated with the high‐resolution X‐ray, radio, and variable UV sources detected at the optical nucleus of this galaxy.
Anca Constantin +2 more
wiley +1 more source
Host galaxies of jetted narrow-line Seyfert 1 galaxies [PDF]
Proceedings of Revisiting narrow-line Seyfert 1 galaxies and their place in the Universe — PoS(NLS1-2018), 2018 We performed $J$-band observations of the host galaxies of nine narrow-line Seyfert 1 galaxies (NLS1). Seven of these sources have been detected at 37 GHz and are likely to host relativistic jets. Host galaxy properties of the jetted NLS1 galaxies are not yet well known, and investigating them is essential to get more insight into their characteristics
Lähteenmäki, Anne +3 more
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